Less than 5 minutes and 50 cents and you'll have taco seasoning that is better than any taco you've ever tried.
Mix all spices together (corn starch and crushed red pepper flakes are optional) and store in an air tight container in a cool dark place like your cupboard. Not by the stove where the heat will deteriorate the spices.
If using newly bought spices the taco seasoning mix should last about a year.
You can add 1/4 teaspoon each of garlic powder and onion powder if you don't wan to cut fresh onions and garlic cloves when making an actual recipe using the spice mix. You WON'T add the freshly cut onions and garlic when making the spice mix, just the dry spices.